Cant get paypal API settings to work in garage sale

I listed a number of cars on ebay using garage sale. Many have ended but buyers can pay paypal. Garage sale said to update API information from paypal which I did. When I test paypal connection popup says security header incorrect. Cant find any reference on paypal-ebay or garage sale to security header. HELP!!

Hi Gary,

you only need to enter your PP credentials if you want to monitor your PayPal accounts for incoming payments.
https://wiki.iwascoding.com/mediawiki/index.php?title=GarageSale_Preferences#PayPal_integration

Otherwise you only need to enter your PP email address.

Regards, Kristian